Heljan Plastic A/S
Old Windmill

4" 10cm Square
Walthers Part # 322-201, p. 531 Walthers 2012 HO Scale Reference
HO scale, $19.98, currently in stock at Walthers

 
This easy-to-build kit consists of prototypically precolored plastic parts and complete instructions. Based on European prototype. With minor modifications, most Heljan kits can be easily Americanized.